|
|
|
The Flint Hills Tall Grasslands covers the Flint Hills of Kansas and the Osage Plains of northeastern Oklahoma. The Flint Hills Tall Grasslands is the smallest grassland ecoregion in North America. It can be distinguished from other grassland associations by the dominance of tallgrass speciesand from the Central Tall Grasslands to the north by its more depauperate biota and a thin soil layer spread over distinct beds of limestone. These flinty beds of limestone, from which the name of this ecoregion is derived, rendered large areas unsuitable for corn or wheat farming. Today, the Flint Hills Tall Grasslands is an anomalyan essentially unplowed (although heavily grazed) remnant of the tallgrass prairie. Historically, fire, drought and grazing by bison (Bison bison) and other ungulates were the principle sources of habitat disturbance in this ecoregion. A new tallgrass prairie national park has been established covering about 44 km2. This ecoregion offers the best opportunity for restoration of tallgrass prairie in the United States (Madson 1993).
The Flint Hills and adjacent Osage Hills contain the last large pieces of tallgrass prairie in the world. The Flint Hills is less rich in species than the Central Tall Grasslands. The dominant grass species in this ecoregion are big bluestem (Andropogon gerardii), switchgrass (Panicum virgatum), and Indian grass (Sorghastrum nutans) (Küchler 1975). Like other ecoregions of this section of North America, bison and elk (Cervus elaphus) once roamed these tallgrass prairies, where they were hunted by the prairie wolf (Canis lupus). These species are now gone, although bison are being reestablished in this ecoregion. Greater prairie chicken (Tympanuchus cupido) are common on the Tallgrass Prairie Reserve. Habitat Loss and Degradation Much of the Flint Hills and the Osage Hills are in relatively good condition. Although grazed by livestock, native common plant species still occur. Remaining Blocks of Intact Habitat This unit contains the largest blocks of "relatively intact" tallgrass prairie among the three tallgrass units and some of the largest blocks in all of the Great Plains ecoregions. Several important blocks of habitat in this ecoregion include:
Degree of Fragmentation Habitat fragmentation is relatively low considering existing land use and level of grazing. Degree of Protection The creation of the Tallgrass Prairie National Park in 1996 adds to the amount of habitat protected in this unit. The Nature Conservancy has also established a large conservation unit in the Osage Hills (Barnard Ranch). Types and Severity of Threats Because this ecoregion is too difficult to farm, future threats of conversion to agriculture remain low relative to other grassland ecoregions. Grazing could become a more severe threat if not properly managed. Some rangeland has been converted to non-native cool-season grass. There is increasing fragmentation due to smaller homestead units being incorporated? into large ranches.
Tallgrass prairie is derived from Sims (1988). It corresponds to Omernik (1995) ecoregion 28 (Flint Hills) and Bailey (1994) section 251F (Flint Hills). Prepared by: S. Chaplin, P. Simms, T. Cook, E. Dinerstein This text was originally published in the book Terrestrial ecoregions of North America: a conservation assessment from Island Press. This assessment offers an in-depth analysis of the biodiversity and conservation status of North America's ecoregions. All text by World Wildlife Fund © 2001 For more general information on this ecoregion, go to the WildWorld version of this description.
|